Bending machines

ABSTRACT

A BENDING MACHINE FOR FORMING A CONE FOR A SHEET HAVING THE SHAPE OF A SEGMENT OF AN ANNULUS, COMPRISING A SLIDE SHOE AT ONE END LOCATED BETWEEN A PAIR OF TRANSPORT ROLLS, AND A PAIR OF BENDING ROLLS ARRANGED ONE ON EITHER SIDE OF THE TRANSPORT ROLLS. THE ROLLS ARE ADJUSTABLE TO ENSURE THAT, AS THE SHEET IS BEING PASSED THROUGH THE   MACHINE, THE SHORTER EDGE IS PASSED WITH A LOWER SPACED AND FORMED WITH A HIGHER CURVATURE RELATIVE TO THE LARGER ARCUATE EDGE, WHILST REMAINING AT ALL TIMES IN TANGENTIAL CONTACT WITH THE SHOE.

Nov. 30, 1971 c. HAusLER BENDING MACHINES f3 Shoots-Sheet 1 Filed June 9, 1969 Cliff/5 INVE/V To IQ TM v Hfiuuw g i3 Y W M h Nov. 30, 1971 Q HAUSLER 3,623,349

BENDING MACHINES Filed June 9, 1969 2 Sheets-Sheet I Fig.6

INVEA/ 7'02 CHRIST MN Hill/s LER By )ffiewaw /oww Afr W575 United States Patent 3,623,349 BENDKNG MACHINES Christian Hiiusler, Bruggfeldweg 12, Aesch, Switzerland Filed June 9, 1969, Ser. No. 831,480 Claims priority, application Switzerland, Aug. 10, 1968, 12,014/ 68 Int. Cl. B2111 5/14 US. Cl. 72-169 5 Claims ABSTRACT OF THE DISCLOSURE A bending machine for forming a cone from a sheet having the shape of a segment of an annulus, comprising a slide shoe at one end located between a pair of transport rolls, and a pair of bending rolls arranged one on either side of the transport rolls. The rolls are adjustable to ensure that, as the sheet is being passed through the machine, the shorter arcuate edge is passed with a lower speed and formed with a higher curvature relative to the larger arcuate edge, whilst remaining at all times in tangential contact with the slide shoe.

BACKGROUND OF THE INVENTION The present invention relates to a bending machine for forming a cone from a metal sheet in the shape of a segment on an annulus.

Machines of this type having three or four rolls are known. One or two driven rolls move the workpiece until on passing through the adjustable bending rolls it has assumed the desired shape. Since the workpiece has the form of a segment of an annulus, it cannot run straight between the rolls and the speed of passage at the longer arcuate edge must be greater than at the shorter edge. Hitherto, this has been achieved by so disposing the rolls that the workpiece is more firmly gripped at the shorter edge than at the longer edge and by disposing in the machine, usually on the bearings of the bending rolls, two rollers serving as abutments. With a bending machine of this type, the desired work can be carried out without difiiculty; the essential disadvantages of a machine of this type consist in that the output capability is relatively poor and that when the ends of the workpiece have moved away over the region of the rollers serving as abutments, the workpiece must be held manually and forced to slide between the working rolls, in order to ensure that the straight side edge portions of the workpiece are also shaped conically and not cylindrically.

Another disadvantage of known bending machines consists in that with increasing curvature of the workpiece there is an increasing possibility of the workpiece escaping from the zone of action of the rolls.

SUMMARY OF THE INVENTION According to the present invention, there is provided a bending machine for forminga cone from a sheet having the shape of a segment of an annulus, comprising two drivable transport rolls having their axes in a first common plane, two adjustable rotatable bending rolls each movable to be positioned laterally of the space defined between the two transport rolls and, at one end of said rolls, a device for guiding the shorter arcuate edge of a sheet to be bent into a cone, the device comprising a shoe arranged between the ends of the transport rolls and having a width of between 60% and 90% of the diameter of the transport roll, which are mounted in such a manner that the gap between them narrows in the direction from the slide shoe towards to the respective other end of the transport rolls. Preferably, the width of the slide shoe is between 66% and of a diameter of the transport rolls.

According to a particular feature of the invention, the slide shoe is provided with a slide surface, which faces the centre of the machine and which is formed in a first region by a second plane perpendicular to the first common plane and in a second region by two slide surface portions, which are mutually symmetrical in relation to the first common plane and which are inclined at an angle of between 8 degrees and 15 degrees in relation to the second plane. At least one of the two transport rolls may be provided with an annular edge reinforcement at the end adjoining the slide shoe. Advantageously, the axes of the two bending rolls approach one another in the directions of the slide shoe end.

According to a refinement of the invention, the bending machine may further comprise a spray device at or in the slide shoe for lubricating the slide shoe and the adjoining portions of the transport rolls, as well as adjacent surfaces of the metal sheet to be bent.

BRIEF DESCRIPTION OF THE DRAWINGS An embodiment of the invention will now be more particularly described with reference to the accompanying drawings, in which:

FIG. 1 illustrates a schematic plan view of a bending machine embodying the invention;

FIG. 2 illustrates part of a vertical longitudinal section through the transport rolls;

FIG. 3 illustrates schematically and in perspective the relative positions of the individual rolls;

FIG. 4 is a plan view of the slide shoe;

FIG. 5 is a side elevation of the slide shoe; and

FIG. 6 a sectional view on the line VI-VI in FIG. 4.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings, the bending machine illustrated in FIGS. 1 to 3 has four rolls, namely, a top transport roll 1, a bottom transport roll 2, and bending rolls 3 and 4 disposed one on each side of the transport rolls. The top transport roll 1 is mounted in bearings 5 and 6 and the bottom transport roll in bearings 7 and 8. The latter two bearings can be raised and lowered together in order to widen or narrow gap 14 between the two transport rolls 1 and 2 to enable the gap to be adapted to the thickness of the sheet to be bent. As shown in FIGS. 2 and 3, this gap 14 narrows in the direction from the bearings 5 and 7 towards the bearings 6 and 8. The two transport rolls 1 and 2 are drivable via a distributor gear train 9 and universally jointed shafts 10. In order to compensate for the effect of the ditference in length between the two wonkpiece surfaces during bending, a settable slipping clutch 15 is provided.

Each of the two bending rolls 3 and 4 can be individually raised and lowered. As illustrated in FIGS. 1 and 3 of the drawings, the two bending rolls 3 and 4 are so disposed that their axes approach one another in the direction of the left-hand side of the machine in the drawing, so that the workpiece is curved more sharply there than on the other side and that a cone is thus formed.

A slide shoe 11 is disposed between a journal 1a of the roll 1 and a bearing support 7a for the roll 2. The slide shoe is illustrated schematically in FIG. 2 and in greater detail in FIGS. 4 to 6. The width of the slide shoe is somewhat less than the diameter of the roll, thus corresponding approximately to the diameter of the journal 1a, but may also be somewhat smaller or larger, that is to say may amount to between 60% and of the roll diameter. The slide shoe 11 has a flat lower side 11a seated on the bearing support 7a of the transport roll 2, where it is screwed fast. The lower part 11b of its polished slide surface is formed by a plane which is perpendicular to the axis of the rolls, while the upper slide surface region is formed by two slide surface portions 11c and 11d, which are symmetrical to one another in relation to the plane 12 extended through the transport roll axes and which are inclined by an angle of between about 8 degrees and 15 degrees, preferably about 10 degrees, in relation to the plane 1111.

Near the slide shoe 11 or in the slide shoe itself, there is disposed a spray device of a known type (not shown) which lubricates the slide surface 11b, 11c, and 11d of the slide shoe 11 and the adjoining portions of the transport rolls 1 and 2, as well as the surfaces of the workpiece to be bent which slide there. Any suitable known liquid used in shaping machines may be employed as a lubricant; obtaining good sliding properties, it is in itself entirely immaterial whether one sprays the parts of the machine on which the workpiece is to slide or one sprays the parts of the workpiece which slide on the machine parts.

In addition, it is expedient for the rolls, at least the two transport rolls, to be provided with edge reinforcement at the parts adjoining the slide shoe, as shown in FIG. 2, where these reinforcements are designated by 1b and 2b.

In the operation of the bending machine, extending edge 13a of the metal sheet 13 which serves as workpiece, and which has the shape of an annular segment, is introduced between the two transport rolls :1 and 2, as is customary in four-roll machines, and is held fast there by appropriate setting of the spacing of the rolls. The two bending rolls 3 and 4 are now moved upwards to such an extent that they bendingly form the sheet metal workpiece on the latter being transported through the machine by the two transport rolls 1 and 2, as shown in FIG. 3. During this transport, the slide shoe 11 produces braking and continuous rotation of the workpiece about its centre 13b so that in the region between the rolls a radial line of the workpiece always lies parallel to the axes of the rolls. Since the gap 14 between the transport rolls 1 and 2 narrows from the slide shoe :11 in the direction of the other end of the rolls, the workpiece 13 is held fast and pulled at a position on the longer arcuate edge 130, while the surface parts adjoining the shorter arcuate edge 13d slide between the rolls, since their speed of displacement is lower than the surface speed of the rolls, the workpiece 13 being of course continuously turned by the slide shoe 11 about its centre 13d, so that the workpiece edge 13d lying against the slide shoe 11 always lies tangentially to the slide surface 11b. Since the gap between the two transport rolls narrows in the direction away from the slide shoe, there is no danger that the workpiece 13 will wander away from the slide shoe 11; the driven transport rolls can thus effect transport to-and-fro in the machine without any manual assistance until the cone is completed, while as is usual, the bending rolls 3 and 4 have to be set slightly higher after each pass.

I claim:

1. A bending machine for forming a cone from a metal sheet having a uniform thickness and a relatively short interior arcuate edge and a relatively long outer arcuate edge, comprising first and second transport rolls, transport roll support means rotatably mounting said first and second transport rolls for rotation with their axes in substantially a common plane and having their surfaces spaced apart to define a workpiece receiving nip therebetween, the spacing between said first and second transport rolls being greatest at one of their common ends than at their opposite common ends, a guide shoe disposed between said first and second transport rolls adjacent the ends in which the spacing therebetween is the greatest and defining an arcuate guide face adapted to tangentially contact and guide the relatively short interior arcuate edge of the workpiece through the nip of said first and second transport rolls, the spacing of said first and second transport rolls being such that the portion of the workpiece adjacent the relatively long outer arcuate edge is engaged more firmly and driven by said transport rolls than the portion of the workpiece adjacent the shorter arcuate edge of the workpiece, a first bending roll mounted adjacent one side of said first and second transport rolls, a second bending roll rotatably mounted adjacent the opposite side of said first and second transport rolis, bending roll support means rotatably mounting said first and second bending rolls on respective opposite sides of said transport rolls in a manner to adjustably position said rolls to engage the workpiece being fed between said first and second transport rolls and to bend the workpiece into a conical formation as it is being fed, said guide shoe being of a width which is from between 60 to 90% of the diameter of said first and second transport rolls, said guide shoe having a slide surface facing inwardly toward the center of the nip between said first and second transport rolls which is formed in a first region by a second plane extending substantially perpendicular to the common plane of the axes of said first and second transport rollers, said slide surface having a second region comprising two side surface portions which are mutually symmetrical in relation to said common plane of the axes of said first and second transport rollers, said side surface portions being inclined at an angle from 8 to 15 degrees in relation to the second plane.

2. A bending machine, according to claim -1, wherein said guide shoe has a width of between 66% and of the diameter of said first and second transport rolls.

3. A bending machine, according to claim 1, wherein said transport roll support means comprises a base having a pair of support frames mounted thereon at axially spaced locations, and bearing means carried by said support frames for rotatably supporting respective ends of said first and second transport rolls on said support frames, said bearing means comprising at least one set of hearings on at least one of said supports which are adjustable to valrly the spacing between said first and second transport re s.

4. A bending machine, according to claim 3, including means mounting said bending rollers in said support frames with their axes converging toward the end having said slide shoe.

5. A bending machine, according to claim 1, wherein at least one of said first and second transport rolls is provided with an annular edge reinforcement adjacent said slide shoe.

References Cited UNITED STATES PATENTS 104,527 6/1870 Woodward 72-175 352,172 11/1886 Wiesner 72173 521,417 6/1894 Orr 72-175 1,568,905 '1/1926 Munro 72175 X 2,759,514 8/1956 Knost 72173 X 2,995,171 8/1961 Hausler 72l75 X 3,016,082 l/l962 Miller 72175 3,287,953 11/1966 Boldrini 72-473 X MILTON S. MEHR, Primary Examiner US. Cl. X.R. 72l7l, 172, 173 

